The role of diffusion and perfusion magnetic resonance imaging in differentiation of haemangioblastomas and pilocytic astrocytomas

Abstract

PurposeHaemangioblastomas (HABLs) and pilocytic astrocytomas (PAs) are brain tumours presenting similar appearance and location in conventional magnetic resonance (MR) imaging. The purpose of our study was to determine whether a detailed analysis of diffusion (DWI) and perfusion (PWI) characteristics can be useful in preoperative differentiation of these tumours.Material and methodsThe study group consisted of biopsy proven six HABLs and six PAs, which underwent preoperative standard MR examinations including PWI and DWI. In PWI relative cerebral blood volume (rCBV) and the shape of perfusion curves (parameters of peak height – rPH and percentage of signal recovery – rPSR) were analysed. All perfusion parameters were measured for the entire tumour core (mean rCBV, mean rPH, mean rPSR) and in regions with maximal values (max rCBV, max rPH, max rPSR). In DWI parameters of apparent diffusion coefficient (ADC) from the entire tumour core (mean ADC) and in regions with minimal values (min ADC) were evaluated.ResultsCompared to PAs, HABLs presented significantly higher rCBV and rPH values and lower mean rPSR value. PAs showed significantly lower rCBV and rPH values and higher mean rPSR value. Mean rCBV showed no overlap in the values between HABLs and PAs, and thus it provided the highest accuracy in differentiating between them. Max rPSR, mean ADC, and min ADC did not show any significant differences.ConclusionsHigh rCBV values and deep perfusion curves with only partial return to the baseline are characteristic features of HABLs differentiating them from PAs, which show lower rCBV values and perfusion curves overshooting the baseline. Diffusion parameters are not useful in differentiation of these tumours.

Do Intratumoral And Peritumoral Apparent Diffusion Coefficient (ADC) Values Have A Role In The Diagnosis Of Pediatric Brain Tumors?

“…The calculated ADC values from the peritumoral areas of hemangioblastoma were higher than pilocytic astrocytoma. According the study of Malgorzata et al (22) the intratumoral mean and minimum ADC values of the hemangioblastoma and the pilocytic astrocytoma were close to each other. This may support the usability of peritumoral ADC values rather than intratumoral ADC values for the differentiation between two tumor groups in childhood.…”

Advanced magnetic resonance imaging findings of cerebellar hemangioblastomas: A report of three cases and a literature review

“…Advanced MRI techniques can help to differentiate PAs and Mets from HBs. HBs often show prominent rCBV values, increased ADC values, and high Lip/Lac without necrosis, while PAs show mildly increased rCBV ratio ranges of 1.40–1.82, 37 – 39 iso to increased ADC value ranges of 1.11–1.64 × 10 −3 mm 2 /s, 26 , 37 – 39 and high Lip/Lac without necrosis. 8 , 32 , 33 Finally, Mets show mild to prominent increased rCBV ratio ranges of 2.55–10.80, 9 , 11 , 12 , 40 – 45 decreased to mildly increased ADC values ranges of 0.79–1.35 × 10 −3 mm 2 /s, 9 , 11 , 12 , 41 , 42 , 44 and high Lip/Lac with necrosis.…”

“… 10 , 25 In contrast, increased ADC has been reported in cerebellar HBs, with values in the range of 1.27–1.55 × 10 −3 mm 2 /s. 9 – 11 , 26 HBs are characterized by the presence of a network of capillary-like channels separated by stromal cells. The increased ADC values could be attributed to the high vascular spaces of capillaries as well as low cellular attenuation in HBs.…”

“…In our cases, three advanced MRI techniques, namely, DWI, DSC-PWI, and MRS, provided characteristic information that is not available with conventional anatomic MRI alone for the imaging diagnosis of cerebellar HBs. Several studies have evaluated HBs using one of these three advanced MRI techniques, 10 , 13 – 15 few studies have evaluated the usefulness of two of the three techniques for differentiating between cerebellar HBs and other cerebellar tumors, 8 , 9 , 11 , 26 and no study has reported whether combining all three advanced MRI techniques could help in diagnosing HBs or more reliably differentiating HBs from other tumors. High ADC, CBV, and Lip/Lac are characteristic findings of cerebellar HBs as described above.…”

Differentiation between supratentorial pilocytic astrocytoma and extraventricular ependymoma using multiparametric MRI

“…The role of rCBV values in differentiating PAs from high-grade gliomas have also been recognized in the literature. However, these investigations have not separated the STPAs and STEEs from those infratentorialy and intraventricularly, or not taken the STEEs as high-grade gliomas into consideration (25,27,34,38,39). Perfusion-related research about unique STPAs and STEEs has only been reported in limited case reports as far as we know (22,24,25).…”